Webpage Feature

On a Mission

Wildflower Center ecologists help restore San Antonio riverbanks

Check out these riparian plants that now can be seen at San Antonio’s Mission Reach. They might be suitable for other landscape projects where wet conditions are common.

Eastern cottonwood (Populus deltoides)
Fun fact: Although short-lived, this tree can grow as much as 5 feet annually on favorable sites in the Mississippi Valley. Photo by Sally and Andy Wasowski.

Black walnut (Juglans nigra)Fun fact: Of all the native nut trees of North America, the Black Walnut is the most valuable save only the Pecan (Carya illinoinensis). Photo by Sally and Andy Wasowski.

Black willow (Salix nigra)Fun Fact: One of the lightest of all Eastern hardwoods, it is extremely weak in a structural sense. Yet when nails are driven into it, black willow remains resilient and does not split. Photo by Joe Marcus.

ABOVE: San Antonio's new Mission Reach connects residents and tourists with four of the city's 18th-century missions and provides public nature space for exercise, meditation and communing with nature. Photo by Lee Marlowe, San Antonio River Authority.

The Wildflower Center showed its savvy about choosing plants that help solve environmental problems as consultant to the $246 million San Antonio River Authority Mission Reach project. As a subcontractor to Jacobs Engineering, Center ecologists chose the best riparian plants for the U.S. Army Corps of Engineers restoration project that turned a concrete-laden dumping ground into an environmental playground.

Intended to connect tourists and residents with four of the city’s 18th-century missions along restored San Antonio Riverbank, the site does that and more by linking visitors with the city’s ecological heritage. In place of concrete, trash and invasive plants running amok on the eight miles south of the city, there are 20,000 trees and shrubs representing 39 native Texas species. Mixed amongst them are more than 60 native species of wildflowers and grasses.

ABOVE: Wildflowers and native grasses representing 60 native Texas species have taken the place of concrete, trash and invasive plants along an eight-mile stretch of San Antonio River. Photo by Lee Marlowe, San Antonio River Authority.

Wildflower Center ecologists are proud to have played a part in creating a public space that in addition to serving as the front door to the historic missions provides trails to hike and bike, picnic spots and wildlife viewing.

Mark Simmons, Ph.D., directs the Wildflower Center’s research and consulting group and led the team that recommended native riparian plants for the Mission Reach and appropriate soil conditions for them to thrive. He says it was exciting to be involved in a river restoration project that emphasized ecological function in addition to flood control. The Ecosystem Design Group he leads has consulted on the ecological function of dozens of sites including the Bush Presidential Center that opened at Southern Methodist University in Dallas earlier this year. Its award-winning research also resulted in Habiturf® — a mix of regionally native turfgrass species that perform better and require fewer resources in the Southwest than traditional non-native turfgrasses.

ABOVE: More wildflowers equal more wildlife including insects like this roseate skimmer dragonfly. Photo by Lee Marlowe, San Antonio River Authority.

Mark Simmons, Ph.D., oversees the Wildflower Center’s research and consulting group that worked on the San Antonio River Authority’s Mission Reach project. He considers riparian plants to be widely underused in the landscape trade. They’re not so different from non-riparian plants, he notes though, and should be a top choce for sites that mimic river and bog conditions. And many can grow far from river conditions if given the right start.

“It depends on the species but for some the only difference will be that they need additional water to establish within the first few years,” says Simmons. “Some that tolerate compacted, low oxygen soils — saturated soils — do well as street trees, such as the sycamore.”

Bringing their knack for picking plants best suited for a particular site to the river restoration project, Simmons’ team had to survey portions of the San Antonio River that were less degraded than the project site to help guide the process. Then they identified which plants grow together naturally and shared habitat along the river. That led to grouping plants together that could tolerate different degrees of moisture and then planting those groups appropriate distances from the water.

For example, cottonwood, sycamore, pecan, cedar elm and black willow trees occur naturally near the river in areas along the Mission Reach because they can withstand a lot of water in the event of flooding. Trees known for having drier tendencies such as huisache, mesquite, spiny hackberry and Brazil wood are better planted toward a river’s outerbanks.

Next time you’re in San Antonio, check out this new spot that puts historic missions and the environment within reach.